John A. Roebling by Dr

Great Achievements notable structural engineers John A. Roebling By Dr. Francis E. Griggs, Jr. P.E. & PLS at the Pedagogium in nearby Erfurt, he was on a feeder canal to the Pennsylvania Canal, enrolled in the prestigious Berlin Bauaka- followed by location surveys for the Allegheny® demi in Berlin where he studied engineering and Portage Canal between Johnston and Hol- under Johann Eytelwein and philosophy un- lidays which was completed in mid 1839. His der Georg Hegel. Then he embarked on the next project was locating a line for the Har- mandatory three-year on-the-job training. Af- risburg and Pittsburgh Railroad across the Al- ter graduating in 1827, he went to work for legheny Mountains, which took him through the government but found it to be extremely late 1841. bureaucratic. He apparently never took the fi- nal exam to become a Baumeister (Building Master). In 1830, after three years of what he calledCopyright “an army of councilors, ministers, and other officials discussing the matter for ten years, making long journeys, and writing long reports, while money spent in all these preliminaries comes to more than the actual accomplishment of the enterprise,” he decided to go to America. He remembered the words of Hegel, who called America “a land of hope John A. Roebling for all who wearied of the historic armory of Roebling is perhaps the most well known Europe.” He and his brother Carl immigrated American civil engineer of the 19th century to America and found an agricultural utopia Brooklyn Bridge (Courtesy of HAER) due to D. B. Steinman’s book The Builders for Germans who sought to escape the repres- of the Bridge and David McCullough’s The sive conditions rampant in most of Europe at While becoming progressively more respon- Great Bridge. In addition, Ken Burns’ series the time. sible for canal and railroad projects, he never on the building of the bridge expanded his He arrived in Philadelphia August 6, 1831 seemed to have forgotten his interest in sus- reputation significantly. This brief biographi- where he would see the bridges over the pension bridges dating from his last year at cal sketch cannot do justice to a remarkable Schuylkill River by Timothy Palmer and Lew- the Berlin Bauakademi, when he visited an career, but it may create an interest in the is Wernwag. Shortly after he and his brother iron chain suspension bridge in Bamberg, Ger- reader to study the existing books on Roemagazine- went to Pittsburgh via the early Pennsylvania many in 1830. In late January 1840, he wrote ® bling. This article of necessity omits the large canals to Huntington. and then over the Al- to Charles Ellet (see STRUCTURE magazine, numberS of patents heT received, his Rvast con- leghenyU Mountains byC wagon trails toT his des- OctoberU 2006) who R proposed a wire E suspen- tributions to the journals of his day, his wire tination. After a brief search for land on which sion bridge over the Schuylkill River in 1839 factory accomplishments and the dozens of to start his community, he purchased a parcel and who was seeking the contract to build a unsuccessful proposals he made for bridges 25 miles north of Pittsburgh in Butler County. bridge on the abutments of Wernwag’s Co- around the country. After a brief summary For the next six years he sought to build up this lossus Bridge that burned in 1838. Ellet was of his early life and engineering accomplish- community, called Saxonburg, by encourag- supportive, but he did not have a contract at ments, this article covers his major suspen- ing more emigrants and clearing more land. In the time. Later Roebling was approached by sion bridges built between 1845 and 1869. 1836, he married another German emigrant, another contractor to assist him in building He was born in Mulhausen, Germany on Johanna Herting, and they had eight children the bridge, as he apparently thought he had the June 12, 1806 the youngest of five children. over the next decade. While successful in his contract. Unfortunately for the contractor, His father ran the local tobacco shop, and his effort to build a community, he found that and Roebling, the contract was later awarded mother aspired for great things from her chil- farming was not fulfilling. The next year to Ellet who built the bridge in 1842. To pro- dren, especially John (Johann). After studying was pivotal in his life as his brother died, he became a United Craig E. Barnes, P.E., SECB States citizen, his first Michael S. Teller, A.I.A. ADVERTISEMENT Information, – For Advertiser son Washington was Wayne R. Lawson, P.E., SECB born on May 26th, and visit

www. he left farming and re- 250 Dorchester Ave., Boston, MA 02127-1835

turned to his engineer- structure ing career as a surveyor 617 268.8977 • 617 464.2971 fax [email protected] on the Sandy and Bea- mag.org ver Canal. This brief Structural Engineering, Architecture, assignment was inter- Condition Surveys, Roofing,

rupted by the financial Moisture Mitigation Design, panic of 1837. He soon Historical Restoration Allegheny Aqueduct 1845 obtained employment

STRUCTURE magazine 79 November 2006 them into place, connecting them with pins to pendulums he placed at the top of his towers to ensure equal pull at the top of each tower. This bridge was opened in February 1845, only eight months after the fire. The bridge description was also carried in the American Railroad Journal in April 1846. For the first time he used diagonal® stays of iron bars, which became characteristic of Roebling bridges. With these two bridges, his reputation spread and placed him on a par with Charles Ellet in the minds of many. It was replaced in 1883 with a bridge designed by Gustav Lindenthal. In 1847, he proposed much longer span Niagara Falls Bridge, Currier and Ives bridges at Niagara Falls, St. Louis, Cincinnati, mote his interests he wrote an article on sus- of 16.5 feet at the top, 14 feet at the bottom and Wheeling in competition with Charles pension bridges in April 1841 in the American and a depthCopyright of 8.5 feet. Towpaths on each Ellet and others. However, Ellet received con- Railroad Journal following Ellet’s article in side were built for mules that pulled the canal tracts to build the Niagara Falls and Wheeling the same journal in 1839. While unsuccess- boats. This bridge opened May 22, 1845. He Bridges, with no action being taken for the ful in gaining his first opportunity to assist immediately wrote an article for the American other two. Ellet opened his Wheeling Bridge in the building of a wire Railroad Journal describing with its 1,010-foot span in 1849 and his 800- cable suspension bridge, his bridge. foot Niagara Bridge in 1848. he turned his interest to Just prior to the open- In 1848, Roebling was approached by the D the design and fabrication ing of his aqueduct, a mas- & H Canal to submit a plan for an aqueduct, of twisted wire cables to be sive fire spread over the city similar to his Pittsburgh structure, over the used on the inclined planes and burned the Wernwag Delaware River at Lackawaxen and another of the Portage Canal. Prior bridge on Smithfield Street over the Lackawaxen River just upstream from to his invention, the ca- Smithfield Street Bridge Monongahela over the Monongahela River its intersection with the Delaware. In com- nal boats were hauled up River Pittsburgh 1846 (built in 1818). Roebling petition with a trussed wooden structure, his inclined planes by 7- to was given the contract to plan was selected. The original method used 9-inch circumference hemp ropes, which had rebuild the bridge as a suspension bridge on to cross the Delaware had not worked and the a very short life. He proposed that he build a the same piers. After rebuilding and raising company was looking at rerouting the canal, twisted wire rope for use by the Canal Com- the piers, he built a bridge with 8 main spans resulting in the need for two river crossings. pany. His request was approved, but he wasmagazine to of 188 feet with two anchor spans, for a total The first bridge, completed in late 1848, was supply the wire rope at his own risk. He built length of 1,500 feet. Due to the small size of a four span bridge with three river piers. In his ropeS on his farm T at Saxonburg R with the his Upiers, he adopted C cast iron columnsT and earlyU 1849, he completedR the secondE bridge assistance of the residents of the community, fabricated the cables on shore. He then lifted and the canal opened in April 1849 with both and used a ropewalk similar to the method used in hemp rope fabrication. He placed the wire rope into position as a trial, but un- fortunately it broke under the load. It was lat- er determined that someone cut the wire at a splice, and the company authorized Roebling to furnish the plane with new rope. After this he received the contract to replace all hemp ropes with his twisted wire cable. This was the beginning of this type of cable that continues to be used in the present day. In mid May of 1844, he received his next opportunity to build a wire cable suspension bridge when the old 1836 wooden aqueduct built over the Allegheny River was determined to be unsafe. He entered a competition, along with 43 other men, to win a $100 premium to replace the bridge. In August, he was noti- fied that his design for a bridge in which the trunk carrying the water was supported by wire cables was awarded the premium. He was issued a contract to build the bridge. Us- ing some of the existing piers for his towers he built a seven span bridge with each span being 162 feet and a trough with a width D & H Aqueduct Sites. Courtesy of Manville B. Wakefield.

STRUCTURE magazine 80 November 2006 aqueducts in service. Based upon the success of these two bridges, he was awarded contracts to build a bridge at High Falls over the Rond- out Creek and one over the Neversink River at Cuddebackville that he finished in 1850. They were both single span bridges, with the High Falls Aqueduct a 135 foot span and the Neversink Aqueduct a 170 foot span. ® All four of his aqueducts were in use until late 1898 when the canal closed. The Delaware River structure was the only one suited for adaptive reuse, and it was sold and converted into a roadway toll bridge with the roadway on the bottom of the trough. It was later purchased by the National Park Service and restored in 1995. It is the oldest extant suspension bridge in the country. In 1851, three years after Ellet was removed Copyright as engineer of the Niagara Bridge, Roebling was retained to complete the project. At that Smithfield Street Bridge profile and section time he determined that, unlike Ellet’s single 1852 and the towers in late 1853. Robert skeptical, that the practicability of Suspended deck structure, he would build an 820-foot Stephenson wrote in a letter to Roebling, Railway Bridges, so much doubted heretofore, long double deck structure, with the railroad “If your bridge succeeds, then mine have has been successfully demonstrated…Bridges on the upper level and the carriageway and been magnificent blunders.” Stephenson, the of a half a mile span, for common or Railway pedestrian way on the lower level. Earlier builder of the Menai Straits and Conway travel, may be built, using iron for the cables in 1847, he submitted proposals for both a tubular bridges, was in Canada building his with entire safety but by substituting the best single level and a double deck structure. He tubular bridge over the St. Lawrence River. quality of steel wire, we may nearly double the submitted his report to the Bridge Companies The Niagara Bridge was opened on March 16, span, and afford the same degree of security.” (one Canadian and one American) on July 28, 1855 with Roebling writing that “One single The bridge was upgraded several times by 1852. Financing was slow and he did not be- observation of the passage of a train over Leffert L. Buck before being replaced August gin construction on the anchorages until late the Niagara Bridge will convince the most 27, 1897. Buck built an open spandrel arch magazineADVERTISEMENT – For Advertiser Information, visit www.STRUCTUREmag.org SLET AEGIS THELP R YOU T URNU CG TREEN U R... E INTO GREEN

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STRUCTURE magazine 81 November 2006 In 1898, the bridge was upgraded and strengthened by the placement of two additional cables and steel trussing by Wilhelm Hildenbrand, a Roebling protégé. The Common- wealth of Kentucky purchased it in 1953, and continued to collect tolls until 1963 when it was® made a free bridge. On June 27, 1993 it was officially renamed the John A. Roebling Suspension bridge. During the pause in construction of the Cincinnati Bridge, Roebling was awarded a contract to replace another Wernwag six span wooden bridge in Pittsburgh across the Al- Copyright legheny River at Sixth Street (for- merly St. Clair Street). For the first time in his career, money was read- ily available and in 1859 he wrote, Allegheny River Bridge 1860 to 1891 when the towers were completed, “The bridge will be beautiful.” It was a four span bridge double deck, twin track bridge under the 1849 charter stated there be no piers in the riv- with main span lengths of 344 feet and shore Roebling Bridge without interrupting traffic. er, a minimum span of 1,400 feet and a deck spans of 177 and 171 feet. For the first time Even with Roebling’s statement that railroad height of 112 feet, but the 1856 charter cut the Roebling used wrought iron side trusses (rail- suspension bridge spans over a mile long were minimum span length to 1,000 feet and the ings) to stiffen his deck, and towers consisting feasible, no one else built a suspension bridge to clearance to 100 feet. After getting his tower of four cast iron posts tied together with lattice carry railroad traffic, as the cantilever bridge be- foundations in and starting the masonry, the wrought iron strapping. He used four cables, came the preferred long span railway structure. company ran into financial problems during two on each side and placed ornamental spires, At the same time Roe- the panic of 1857 and work etc. on top of each tower. His son Washington bling was working on Ni- stopped. With the advent worked with him on this project. When John agara, he was awarded a of the Civil War, the proj- was back at Cincinnati, Washington was left contract in 1853 to build a ect was virtually shut down in charge of the bridge. When completed in 1,224-foot long single track until work resumed slowly 1860, Engineering News wrote that it was “con- suspension bridge to carry magazinein 1863. The towers and sidered the finest in the world…and…a struc- the Lexington and Danville anchorages were finished in ture of importance in the history of bridges.” RailroadS over the KentuckyT R U 1864.C Near the endT of the It lastedU until 1891 whenR it was replacedE with River. Between 1853 and War his son Washington, a bridge by Theodore Cooper. 1868, he built the masonry Cincinnati Covington Suspension who graduated from Rens- Bridge 1868 to Present In 1867, Roebling was selected as Chief towers and anchorages and selaer Polytechnic Institute Engineer for the proposed Brooklyn Bridge had wire delivered to start spinning the cables, in Troy, NY in 1857, was discharged from the across the East River connecting Manhattan when the company went bankrupt stopping Army and took over the job of spinning the and Brooklyn. He began working on a design construction. Between 1855 and 1868 he kept cables and hanging the deck. The bridge was for the bridge starting in the mid 1850s, with in touch with individuals who proposed com- finished in late 1866 and formally opened on Abram Hewitt his associate from Trenton, NJ. pleting the railroad and bridge, but no further January 1, 1867. work was done until C. Shaler Smith built a cantilever bridge over the gorge in 1877. On August 18, 1856, Roebling signed a contract to build a bridge across the Ohio River connecting Cincinnati and Covington, KY. Earlier, in 1847, he submitted as plan for a bridge with a pier in the middle of the river flanked by two 800-foot spans to shorter tow- ers with 200-foot spans from the short tow- ers to the anchorages. His proposal was chal- lenged by shipping interests as restricting river traffic. The bridge company was not success- ful in getting its charter amended until 1856, after which Roebling wrote a new report for a single span bridge 1,057 feet in span, or 47 feet longer than Ellet’s Wheeling Bridge that opened in 1849 and collapsed in 1854. The Proposed Brooklyn Bridge 1870

STRUCTURE magazine 82 November 2006 study advances made in the use of pneumatic adjoining cities, and they will be entitled to caisson while the report was being compiled. be ranked as national monuments. As a great Funds to build the bridge were slow in com- work of art, and as a successful specimen of ing, so work did not start until mid 1869. advanced Bridge engineering, this structure During the survey for the bridge’s location, will forever testify to the energy, enterprise and Roebling’s foot caught between some timbers wealth of that community, which shall secure on the ferry dock and was crushed. After its erection.” several weeks, he contracted lockjaw and died Between 1869 and 1883, his son Washing® - on July 22 before any work had been done ton, who made many changes in the design on the bridge. The Scientific American wrote: and choices of materials, built the bridge. It “Altogether few men have lived whose history was the capstone to a remarkable career. Af- can record a series of more brilliant successes ter 123 years, it continues to serve the citizens than that of Mr. Roebling. He leaves behind of New York. As Roebling predicted, it is “the him monuments of his greatness, and his name great engineering work of this continent, and will pass into history among the brightest of the age.”▪ of those who have achieved immortality, by Niagara lower deck and side trusses benefiting the human race. That he has been Copyright Dr. Griggs specializes in the restoration of He wrote letters promoting the construction cut off thus on the threshold of his greatest th of the bridge in 1857, 1860 and 1864, but the undertaking, adds to our sincere regret; but historic bridges, having restored many 19 time was not right until the winter of 1867 that he could not live to see its completion will Century cast and wrought iron bridges. when a severe ice jam closed the ferries across not detract from the well won renown of its He was formerly Director of Historic the river. A charter was approved for the bridge gifted and accomplished designer.” Bridge Programs for Clough, Harbour & in April 1867 and Roebling was assigned a Roebling’s vision of his bridge was con- Associates LLP in Albany NY and is now contract to not only design the bridge, but also tained in his report when he wrote: “The an independent Consulting Engineer. supervise its construction for $8,000 per year. contemplated work, when constructed in ac- Dr. Griggs can be reached by email at He presented his report to the Bridge Com- cordance with my design, will not only be the [email protected] pany in September for a bridge with a span greatest Bridge in existence, but it will be the of 1,600 feet, with the railway and carriage- great engineering work of this continent, and way on the same level and a central elevated of the age. Its most conspicuous feature, the Dr. Griggs thanks Don Sayenga promenade. Washington went to Europe to great towers, will serve as landmarks to the for his help on this article. magazineADVERTISEMENT – For Advertiser Information, visit www.structuremag.org S TSTRUCTURAL R ENGINEERS U REFRESHER C COURSET U R E Review for the Illinois State Board of Examination November 9, 2006—March 29, 2007

DESCRIPTION: The Structural Engineers Association of Illinois (SEAOI) offers an in-depth review of structural engineering principles and applications to help prepare candidates for the Illinois Structural Engineers State Board Examination (to be held April 20–21, 2007). Classes are taught by practicing structural engineers with experience as university faculty and in professional practice. CONTENT AREAS: Exam Details November 9, 2006 Geotechnical Design November 13, 16 and 20, 2006 Structural and Steel Design November 27, 30, December 4, 7, 11, 14, 18, 21, 2006, January 4, 8, 11, 2007 Earthquake Resistant Design January 18, 22, 25, 29, February 5, 8, 2007 Structural Concrete February 1, 12, 15, 19, 22, 26, March 5, 2007 Masonry March 8, 12, 15, 2007 Timber Design March 19, 22, 26, 29, 2007 WEB ACCESS: This course, either in its entirety, or by particular content area, can be accessed via the Web. LOCATION: The course will be offered in downtown Chicago. All sessions are from 6:00–7:45 p.m. on Mondays and Thursdays. FEES: The cost is $1,025 for the entire course ($925 for SEAOI members). For a particular content area, the cost is $65 per session ($50 for members). QUESTIONS: Contact the SEAOI office at 312.649.4600 x200 or visit the website at www.seaoi.org

STRUCTURE magazine 83 November 2006

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